Let's say that you wanted to make a cake which needed 2 cups of milk. Could you estimate a conversion of two cups of milk to liters?

This Concept will teach you how to estimate between customary and metric units of measurement.

Guidance

While you encounter the
Customary System
of measurement all of the time in your everyday life, there is another system of measurement that is also widely used. This system is known as the
Metric System
. In other countries people use the metric system for the same things that we use the customary system for. We might weigh grapes using pounds, but in France they use grams to weigh grapes. You may measure the length of one side of your backyard in feet, but in Beijing they use meters. Even in the United States, the metric system is frequently used especially in science.

You may find yourself in a situation where you need to convert between the metric system and the customary system. Take a look at the chart below. It shows the
estimated
customary equivalent to common metric units.

Metric Units

Customary Units

1 centimeter

0.39 inches

1 meter

3.28 feet

1 kilometer

0.62 miles

1 milliliter

0.2 teaspoons

1 liter

4.23 cups

1 gram

0.04 ounces

1 kilogram

2.2 pounds

Using this chart can help us to estimate the equivalence between metric units of measurement and customary units of measurement. Let’s look at a problem.

Estimate the equivalent measures from 14 centimeters to inches.

A centimeter is equal to about 0.39 inches, so we multiply

Estimate the equivalent measures from 7.7 pounds to kilograms.

There are 2.2 pounds in 1 kilogram, so we divide the number of pounds by the number of pounds in 1 kilogram.

The answer is 3.5 kilograms.

If you keep this chart in mind, you will always be able to estimate measures. If you do this enough, you will be able to figure some of them out without the chart.

Most runners know that a 5k race is about 3.1 miles. Where as a 10k is 6.2 miles.

Here are a few for you to try on your own. Estimate each equivalent metric measure.

Example A

.16 ounces = ____ grams

Solution: 4 grams

Example B

6 pounds = ____ kilograms

Solution: 3 kilograms

Example C

12 feet = ____ meters

Solution: 3 meters

Here is the original problem once again.

Let's say that you wanted to make a cake which needed 2 cups of milk. Could you estimate a conversion of two cups of milk to liters?

To convert cups to liters, let's think about how many cups equals 1 liter.

4.23 cups is equal to 1 liter.

Our recipe calls for a little less than half the cups needed to equal 1 liter.

Therefore, we can say that 2 cups is approximately equal to .5 liters.

This is our answer.

Vocabulary

Here are the vocabulary words found in this Concept.

Customary System

a system of measurement common in the United States. It involves units of measurement such as inches, feet, miles.